[P37]: The Desire that arises from Sadness or Joy, and from Hatred or Love, is greater, the greater the affect is.

Dem.: Sadness diminishes or restrains a man’s power of acting (by P11 S), i.e. (by P7), diminishes or restrains the striving by which a man strives to persevere in his being; so it is contrary to this striving (by P5), and all a man affected by Sadness strives for is to remove Sadness. But (by the definition of Sadness) the greater the Sadness, the greater is the part of the man’s power of acting to which it is necessarily opposed. Therefore, the greater the Sadness, the greater the power of acting with which the man will strive to remove the Sadness, i.e. (by P9 S), the greater the desire, or appetite, with which he will strive to remove the Sadness.

Next, since Joy (by the same P11 S) increases or aids man’s power of acting, it is easily demonstrated in the same way that the man affected with Joy desires nothing but to preserve it, and does so with the greater Desire, as the Joy is greater.

Finally, since Hate and Love are themselves affects of Sadness or of Joy, it follows in the same way that the striving, appetite, or Desire which arises from Hate or Love will be greater as the Hate and Love are greater, q.e.d.